Three Dy() single-ion magnets bearing the tropolone ligand: structure, magnetic properties and theoretical elucidation

The reactions of dysprosium nitrate with the main ligand of tropolone (HL) in the presence of ancillary ligands of phenanthroline (phen) or 1,3,5-benzenetricarboxylic acid (H 3 BTC) gave three mononuclear complexes, [Dy(phen) 2 (L)(NO 3 ) 2 ] ( 1 ), [Dy(phen)(L) 3 ]·H 2 O ( 2 ) and [Dy(H 3 BTC)(H 2 O)(L) 3 ] 2 ·3H 2 O ( 3 ). They present different sets of mixed ligands. The Dy( iii ) ions are ten-coordinated to build a bicapped square anti-prismatic geometry for complex 1 and eight-coordinated in dodecahedral geometries for complexes 2 and 3 . Their magnetic properties were investigated in detail. Complexes 1 and 2 are single ion magnets under an external field, and complex 3 is a single ion magnet under zero field. This revealed a tuning effect on the performances of single ion magnets from ancillary ligands. These experimental magnetic behaviours are supported by the results from ab initio calculations, including g -tensors, averaged transition magnetic moments, magnetic easy axes, and crystal field parameters. Three Dy( iii ) SIMs bearing the tropolone ligand are reported here with the tuning effect on their performances by ancillary ligands revealed via experimental magnetic investigations and theoretical calculations.